Prefabricated construction elements



Oct. 6, 1970 DA COSTA 3,531,902

PREFABRICATED CONSTRUCTION ELEMENTS Filed Jan. 29, 1968 2 Sheets-Sheet l PRIOR ART INVENTOR 2 PEDRO C.C. duCOSTA BYj/tsez ATTORNEYS Oct. 6, 1970 DA COSTA 3,531,902

PREFABRICATED consmucnon ELEMENTS Filed Jan. 29, 1968 2 Sheets-Sheet z INVENTOR PEDRO C.C. dcl COSTA ATTORNEYS United States Patent O PREFABRICATED CONSTRUCTION ELEMENTS Pedro Croner Selestino da Costa, Lisbon, Portugal, as-

signor to Lusalite-Sociedade Portuguesa de Fibro- Cimento S.A.R.L., Cruz Quebrada, Portugal, a limited liability joint-stock company Filed Jan. 29, 1968, Ser. No. 701,362 Claims priority, applicat7io1r2sPortugal, Feb. 6, 1967,

Int. 01. E04c 1/30 U.S. 52588 9 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention The present invention relates to prefabricated construction elements and more particularly to prefabricated construction elements which provide both exterior roofing and interior ceiling structure.

The prior art In a relatively recent development in the area of prefabricated structures prefabricated construction elements formed of thin concrete shells and forming small channel troughs for drainage have been provided for use as roofing structures. These construction elements generally provide roofing structure only and thus where an interior ceiling is required it is necessary to suspend the ceiling from the roof or to support it independently.

Because of the provision of drainage troughs the roofs may be built generally horizontally, the troughs permitting drainage of rainwater to the exterior of the building or to intermediate gutters. These intermediate gutters are oftentimes the beams which support the construction elements. In one example of such a roofing structure the construction elements are adapted to form a corrugated roof with spaced trapezoidal troughs between the corrugations.

Roofing elements of this type are generally constructed of thin concrete shells which have a section modulus adapted to the spans and loads to be supported. The load corresponds to the weight of the construction ele ment itself plus the weight of whatever overloads there may be. The magnitude of the section modulus of the elements utilized is an important consideration in that, in general, the higher the section modulus the greater the strength of the element although beyond a certain point the actual area of roof covered by an element becomes too small when compared with the developed area of the material used in fabricating the element and thus there is material wastage. In general, the higher the section modulus the greater the height of the constructional element and the less the width thereof.

SUMMARY OF THE PRESENT INVENTION In accordance with the present invention there is pro- Patented Oct. 6, 1970 vided a prefabricated construction element which furnishes both ceiling and roofing structure. The prefabricated construction elements of the invention provide several advantageous features. First, when assembled, the construction elements form tight joints between adjacent elements. Second, the upper flanges of the construction elements provide a drainage channel or trough. Third, roof and ceiling structure is provided in a single construction element. Fourth, the construction elements may be of relatively large size in that the section modulus therefor is rather high. It is noted that the disadvantage of a high section modulus, i.e., the relatively little area covered for the amount of material used, is overcome here in that both roof and ceiling are provided and thus an area twice that provided where a roof only were formed is covered In accordance with a presently preferred embodiment of the invention the individual construction elements are generally U-shaped and include a vertical web and horizontally extending upper and lower flanges. The upper flanges include inner and outer curved portions, each preferably in the form of a shallow inverted U. The curved portions together with an intermediate flat section form a drainage trough or channel. When the elements are assembled the outer curved portion of the upper flange of a first constructional element overlaps with the inner curved portion of the upper flange of an adjacent con-- struction element. Preferably the lower flanges are also curved such that tight joints are formed between adjacent constructional elements.

The constructional elements are preferably used in a roofing-ceiling construction but may also be used as walls. In a wall construction the construction elements may be arranged to extend vertically or stacked in a vertical direction.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will become apparent upon consideration of the following description of the invention taken with the accompanying drawings wherein:

FIG. 1 is a sectional perspective view of a prior art prefabricated building construction;

FIG. 2 is a sectional perspective view similar to FIG. 1 of a building construction in accordance with a presently preferred embodiment of the invention;

FIG. 3 is an end view of a single prefabricated building construction element in accordance with the embodiment of FIG. 2 with adjacent construction elements shown in phantom;

FIGS. 4 to 6 are end views similar to FIG. 3 of three further embodiments of the invention;

FIG. 7 is an end view similar to FIG. 3 wherein the lower flange is corrugated;

FIGS. 8 and 9 are end views similar to FIG. 3 of prefabricated construction elements of the prior art which provide both roof and ceiling structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a prior art building construction is shown wherein a roof generally denoted R is formed by a series of substantially identical prefabricated construction elements. Considering construction element 10 as exemplary it will be noted that element 10 generally comprises a pair of outwardly and upwardly extending flanges 10a and 10b and a substantially horizontal flat base portion 100. Flange 10a includes a curved end portion which overlaps with a portion of a flange 10b of an adjacent construction element 10' corresponding to flange 10b. A trapezoidal drainage trough or channel 11 is formed between flanges 10a and 10b. With a construction of this type it is necessary Where a ceiling is desired to support 3 the ceiling independently or to suspend it from roof R. As shown in FIG. 1 a portion of a ceiling denoted 12 is suspended from a pair of beam supports 14 which extend through a wall support 16. Wall support 16 also supports roof R.

Referring to FIG. 2, a building construction is shown in accordance with a presently preferred embodiment of the invention which provides a roof generally denoted 18 and a ceiling generally denoted 20. The prefabricated construction elements are substantially identical and are generally U-shaped in cross-section. Taking construction element 22 as being exemplary the construction thereof can be best seen in FIGS. 2 and 3. Element 22 comprises an upright web 22a and a pair of outwardly extending flanges 22b and 22c. The upper flange 22b includes a pair of curved sections 22d and 22a spaced by an intermediate flat section 22 Curved sections 22d, 22s are formed generally in the shape of a shallow, inverted U, with outer end section 22c being slightly larger than the section 22d adjacent the web 22a..

As will be set forth in connection with FIGS. 4 to 6 the lower flange 22c may take a number of shapes but preferably includes a pair of curved sections 22g and 22i separated by an intermediate flat section 22h. As shown, curved section 22g curves outwardly from web 22a and then inwardly to terminate in flat section 22h. Curved section 221 extends outwardly from the end of intermediate section 22h at an acute angle to the plane thereof.

When the prefabricated consrtuction elements are assembled, as shown in FIG. 2, the outer curved section 22c of upper flange 22b overlaps with a portion 22d of an adjacent construction element 22". Portion 22d" is a curved section corresponding to curved section 22d of element 22. Similarly, a curved end section 22e' of the upper flange of a construction element 22' located on the opposite side of element 22 overlaps with curved section 22d. This overlapping of corresponding curved sections provides tight lap joints between the upper flanges having excellent waterproofing characteristics. With the construction elements assembled curved section 22i partially overlaps section 22g" of adjacent element 22" while section 22g is partially overlapped by section 22i' of the construction element 22' on the other side of element 22. This construction provides tight lap joints between adjacent lower flanges having improved insulating properties.

Referring to FIGS. 4 to 6, there are shown three additional forms that a lower flange might take. The construction elements of FIGS. 4 to 6, apart from the shape of the lower flanges thereof, are of a form substantially the same as that of the elements of FIGS. 2. and 3. In FIG. 4 the lower flange 24a is merely a flat plate which abuts with the web of the adjacent element. In FIGS. and 6 lower flanges 26a and 28a form Simple joints with portions of the lower flanges of the adjacent sections. In FIG. 5 an end extension of flange 26a is adapted to mate with a recess in an adjacent element While in FIG. 6 an extension projecting beyond the web is adapted to mate with a similar recess formed in the end of a flange of an adjacent element as shown.

The construction element of the embodiment of FIG. 7 is substantially the same as that shown in FIGS. 2 and 3 but incldues a corrugated lower flange 30a. The corrugations are generally provided for aesthetic purposes but may be used in securing insulating or finishing linings to the ceiling structure.

FIGS. 8 and 9 show construction arrangements of the prior art providing both a roof and ceiling. In FIG. 8 a construction element 32 comprises a series of corrugations 32a and an adjoining flat section 32b. As shown in FIG. 8 the corrugations of an adjacent section rests on plate 32b and an end portion of these corrugations overlaps the corrugated member 32a of element 32 adjacent flat section 32b. In FIG. 9 a construction element 34 is of generally rectangular shape and includes a first flange 34a extending outwardly as a continuation of the upper surface thereof and a second flange 34b extending outwardly as a continuation of the lower surface thereof. Element 34 further includes longitudinal recesses 34c and 34d formed in the upper and lower surfaces, respectively. Flanges 34a, 34b form joints with recesses corresponding to recesses 34c and 34d in adjacent construction elements as shown. Similarly, recesses 34c and 34d form joints with flanges corresponding to flanges 34a and 34b on adjacent construction elements. The construction elements of FIGS. 8 and 9 suffer certain disadvantages. Roofing constructed as shown in FIG. 9 generally requires an upper cover in that the joints formed between the elements (10 not have good waterproofing characteristics. Where these construc tions are exposed to Weathering an upper impermeable layer of a material such as cellular concrete or asphalt is utilized.

Returning to the construction assembly of FIGS. 2 and 3 it is noted that the construction elements are preferably constructed of asbestos-cement but may be constructed of other materials. Examples of other materials are steel, aluminum and precast concrete. Using steel or aluminum it is possible to construct a prefabricated element of several dozen centimeters in width and height and several meters in length. With precast concrete an element of about one or one and one-half meters in width and height may be constructed but the use of this material is generally unsatisfactory because the walls are of too thick a construction and thus may be prohibitively expensive. Of course the use of precast concrete in thin sheets may be attractive in certain instances.

It is noted that in their assembled form the construction elements of the present invention provide a substantially rectangular air space which may be filled or partially filled with an insulating material such as glass, rock wool or cork. In other variations a layer of insulating material may be applied to lower flange 220. With this construction the ideal theoretical considerations for roof-ceiling structures are realized, i.e., there is provided an outside surface for protection against the elements, an air space, an insulating section, and an inside surface. In a further variation it may be desirable to provide partial or total filling up of the air space of the construction element with a material such as concrete. Such an arrangement would provide some degree of thermal and sound insulation while furnishing substantial impact resistance.

In accordance with a further modification of the invention the upper flanges corresponding to flange 22b may be formed at a slight angle to the horizontal to provide improved water drainage. The ceiling flange would remain generally horizontal.

Although reference has been made throughout the specification to use of the prefabricated construction elements of the invention in a roofing assembly these elements are also suitable for use in a wall assembly or the like. Referring to FIG. 1, with the construction assembly used as a roof-ceiling structure the assembly may be supported on a horizontal beam 36. There are of course a number of different methods by which the construction elements may be atfixed to a supporting member and by which the elements may be supported. As shown, a series of screws 40 extend through the lap joints formed by the overlapping flange sections and through the base flanges into a securing member constructed of wood or a similar material. The construction elements may alternatively be glued, nailed, riveted or otherwise secured to a support member.

With the construction assembly utilized as a wall the individual construction elements may either be arranged with their longitudinal axes extending vertically and the elements arranged in a side by side relationship or with the longitudinal axes of the elements positioned horizontally and the elements arranged in a stacked relationship. In the former arrangement support element 36 would be a horizontal member and the construction elements would depend downwardly therefrom. Where the construction elements do not extend all the way to the ground surface, hooks may be provided on lower support elements for engaging the edges of the flanges. In the second arrangement support member 36 would be a vertically extending member and constructiton elements would extend perpendicularly outwardly therefrom in a horizontal direction. In both these arrangements the construction elements may, of course, be secured to the support members provided therefor by any of the means described hereinabove. Where the construction assembfy is used as a wall additional reinforcement such as concrete as described hereinabove may be necessary.

The ceiling or inner wall flanges (corresponding to flange 22c of FIGS. 2 and 3) may be lined with suitable materials such as plastics or finished wood. The ends of the construction elements may be left open or partially open to provide ventilation. The air spaces between the flanges when not filled can accommodate building equipment such as pipes, wires, cables and the like.

It will be understood by those skilled in the art that the exemplary embodiments described are subject to modification without departing from the scope and spirit of the invention. Thus it will be understood that the scope of the invention is to be measured not by the illustrative embodiments shown but rather by the subjoined claims.

I claim:

1. A building construction arrangement including an elongate prefabricated construction element generally of U-shaped cross-section comprising a web and first and second outwardly extending flanges, said first flange comprising a first outwardly curved section located adjacent said web, an intermediate straight section and a further outwardly curved section located at the end of said first flange, said first curved flange section constituting means for receiving in overlapping fashion a correspondingly shaped portion of an adjacent prefabricated construction element and said further curved flange section constituting means for engaging in overlapping fashion a correspondingly shaped portion of a flange of a further prefabricated construction element, said first and second flanges being formed such that adjacent construction elements may be assembled by lowering a first construction element beside a second construction element so that the said further curved surface of the first flange of the first element overlaps the said first curved surface of the first flange of the second element, said second flange section including a first section adjacent said web and including a portion extending outwardly of said web, an intermediate section, and a further section located at the end of said second flange and including a portion extending inwardly of said intermediate section, said first section of said second flange constituting means for receiving in partially overlapping fashion a reciprocally shaped portion of a flange of an adjacent prefabricated construction element and said second section of said second flange constituting means for engaging in partially overlapping fashion a reciprocally shaped portion of a flange of a further construction element, the length of said second flange in a direction generally perpendicular to the plane of the web being less than the length of said first flange in said direction such that said second flange will not hinder lowering of a first construction element beside a second construction element.

2. A construction arrangement in accordance with claim 1 wherein said first section of said second flange comprises a first portion curving outwardly from said web in a first direction and second portion curving inwardly of said first portion and terminating in said intermediate section and wherein said further curved section of said second flange comprises a portion curving outwardly of said intermediate section at an acute angle with the plane thereof.

3. A construction arrangement in accordance with claim 1 wherein one of said curved sections of said first flange is formed generally in the shape of a shallow, inverted U.

4. A construction arrangement in accordance with claim 1 wherein both of said curved sections of said first flange are formed generally in the shape of a shallow, inverted U.

5. A construction arrangement in accordance with claim 4 wherein corresponding portions of shaped said U-shaped curved sections lie substantially in the same plane.

6. A construction arrangement in accordance with claim 1 wherein said intermediate section of said second flange is corrugated.

7. A construction arrangement in accordance with claim 1 comprising a plurality of said elongate prefabricated construction elements, said elements being arranged adjacent one another in a horizontal plane to form a roof and simultaneously a ceiling.

8. A construction arrangement in accordance with claim 1 comprising a plurality of said elongate prefabricated construction elements, said elements being arranged adjacent one another with the longitudinal axes thereof extending vertically to form a double wall.

9. A construction arrangement in accordance with claim 1 comprising a plurality of elongate prefabricated elements, said elements being arranged with their longitudinal axes parallel to a horizontal plane in stacked fashion, one on top of the other, to form a double wall.

References Cited UNITED STATES PATENTS 2,164,681 7/1939 Fould 52588 X 2,424,080 2/1947 Engstrom 52731 X 2,926,928 3/1960 Bennett 52588 X 3,332,197 7/1967 Hinkle 52731 3,347,010 10/1967 Richter 52-588 X FRANK L. ABBOTT, Primary Examiner S. D. BURKE, III, Assistant Examiner US. Cl. X.R. 52730 

